Use of two different approaches to the synthesis of nano zero valent iron for sediment remediation

Heavy metals are one of the main pollutants of river, lake and canal sediments. Stabilization technology proved to be an effective method for solving this problem. Stabilization covers a wide range of remediation techniques that are used to transform waste into forms that will be less problematic for the environment. Stabilization of the Great Backi Canal sediment was carried out by using nanomaterials, namely nano zero-valent iron (nZVI). Two different approaches for the synthesis of nanomaterials were used, conventional and so-called "green" method. For conventional, borohydridemethod, nZVI was stabilized with native clay as porous material which proved to be very effective because of its specific surface area. Extract of oak leaves was used for green method which contains polyphenols as promising agents for the nZVI synthesis. Assessment of the treatment efficiency was performed by using semi-dynamic leaching test ANS 16.1. In order to stimulate leaching conditions, similar to those at the landfill, ANS 16.1 method was modified by using humic acid solution. These results showed that metals were successfully immobilized in the sediment.